Vertebroplasty is a modern minimally invasive surgery aimed at restoring the supportive function of a vertebra that has been compromised due to a fracture by injecting a cement-like substance into its body.

As a result, the body of the damaged vertebra restores its axial stability, strengthens, and regains the ability to perform its supportive function. During the polymerization of the bone-cement mixture, thermal energy is released, which causes thermal necrosis of nerve endings, thereby blocking the pain conduction mechanisms at the vertebral level. In cases of tumor or metastatic vertebral involvement, there is an additional effect of tumor cell death. The bone cement, as it polymerizes, exerts a cytotoxic effect on tumor cells while providing support to the affected vertebral body. Once hardened, the cement strengthens the vertebra, which allows not only effective treatment of the consequences of compression fractures of vertebral bodies caused by osteoporosis but also the treatment of pain caused by vertebral body hemangiomas or metastatic spinal tumors. Within a few hours after the procedure, pain regression can reach up to 50% of the preoperative baseline (H. Deramond et al., 1998; J. Mathis, 2002). After several days, and according to some data, up to 2 weeks, significant pain reduction or even complete pain relief is observed in 85% of patients with tumor involvement of the spine and in 90% of patients with compression fractures of vertebral bodies due to osteoporosis. Currently, this method is widely used to treat pain syndrome and pathological fractures caused by metastatic spinal lesions and osteoporosis. The highest number of procedures is performed in the USA and Western European countries.

EFFECTIVENESS OF THE VERTEBROPLASTY METHOD:

Conservative treatment of damaged vertebral bodies does not yield satisfactory results and often leads to secondary complications — worsening osteoporosis, lung congestion leading to pneumonia, deep vein thrombosis of the lower leg, pulmonary artery embolism, etc.

The effectiveness of percutaneous vertebroplasty is very high. This method was developed in 1984 by French neurosurgeon Pierre Galibert and neuroradiologist Herve Deramond. As a result of percutaneous vertebroplasty, they achieved almost 90% pain regression in 38 patients with aggressive hemangiomas. In about 10% of cases, pain levels remained unchanged. The same research group published results of percutaneous treatment of 100 patients with metastatic spinal involvement, with pain regression in 80% of cases.

No cases of increased pain or worsening condition have been reported. Percutaneous vertebroplasty is performed under local anesthesia and is the most effective, modern, and minimally traumatic treatment method, allowing for a hospital stay of no more than 24 hours. Pain reduction and preservation of motor activity significantly improve patients’ quality of life. Thus, the percutaneous vertebroplasty method can be actively recommended for widespread use in treating pathological vertebral fractures.

MECHANISM OF PAIN REGRESSION IN PATIENTS WHO HAVE UNDERGONE VERTEBROPLASTY

MECHANISM OF PAIN REGRESSION

In many studies, vertebroplasty is positioned as a procedure that leads to a stable and long-lasting regression of pain syndrome in pathological vertebral body fractures caused by osteoporosis and neoplastic lesions of the spine. According to several authors, after the procedure, pain disappears or significantly decreases in 90% of patients with compression fractures and in 86% of patients with metastatic spinal involvement.

It is generally accepted that there are three main factors responsible for pain reduction in patients after vertebroplasty:
✔ Mechanical
✔ Thermal
✔ Chemical

❃ THERMAL FACTOR ❃

Caused by thermal necrosis of nerve endings as a result of the exothermic reaction during polymerization. Thermal necrosis of osteoblasts occurs at temperatures above 50°C for more than 1 minute, while apoptosis of osteoblasts occurs at 48°C for 10 or more minutes. In addition, the increase in temperature may play a role in significantly slowing down the growth rate of tumor cells.

❃ CHEMICAL FACTOR ❃

The cytotoxicity of the monomer also contributes to the anti-tumor effect, which is supported by numerous clinical data.

❃ MECHANICAL FACTOR ❃

This is the primary cause of pain reduction, achieved by stabilizing and strengthening the vertebral body, preventing micro-movements at the fracture site, thereby reducing irritation of nerve endings.

❃ ISCHEMIC FACTOR ❃

In cases of tumor involvement, besides the mechanisms mentioned above, the ischemic factor may play a significant role. It is caused by an increase in hydrostatic pressure within the vertebral body due to mechanical displacement of tumor tissue by bone cement in areas of osteolytic activity.

INDICATIONS AND CONTRAINDICATIONS FOR PERCUTANEOUS VERTEBROPLASTY

❁ INDICATIONS: ❁

I. Vertebral tumors (benign tumors such as hemangiomas); metastatic spinal involvement (metastases, multiple myeloma) accompanied by pain syndrome;
II. Compression fractures of vertebral bodies due to osteoporosis accompanied by pain syndrome;
III. Pain syndrome caused by osteonecrosis of the vertebral body (Kummell’s disease, lymphoma with osteolytic component, fibrous dysplasia, eosinophilic granuloma).

❁ CONTRAINDICATIONS: ❁

✔ Any signs of local (osteomyelitis, epidural abscess) or systemic (sepsis) infectious processes.
✔ Coagulopathy (platelets below 100,000; prothrombin time 3 times above the upper limit of normal; partial thromboplastin time 1.5 times above normal).
✔ Spinal cord compression with development of secondary myelopathy.
✔ Allergic intolerance to components of polymethylmethacrylate.
✔ Compression fractures with a decrease in vertebral body height of more than 70% (“vertebra plana”) – technically difficult to perform percutaneous vertebroplasty (PVP).

Radiculopathy and destruction of the posterior wall of the vertebral body are not absolute contraindications for vertebroplasty, although the risk of complications is significantly increased. In such cases, the patient must be informed about the potential negative consequences of the procedure.

TECHNIQUE FOR PERFORMING PERCUTANEOUS VERTEBROPLASTY PROCEDURE

☘ PREOPERATIVE PREPARATION. ☘
Standard examinations before the procedure:
Physical examination, including a detailed neurological status assessment; X-ray imaging of the spine in two projections; CT scan, preferably with 3D reconstruction to determine anatomical parameters of the pedicle roots and integrity of the posterior wall of the vertebral body, and to visualize the spinal canal; MRI to exclude compression of the spinal cord and/or nerve roots; general clinical blood tests and extended coagulation profile. Patients suspected of having metastatic spinal involvement should also undergo oncological screening, including bone scintigraphy.

☘ PREOPERATIVE ANTIBIOTIC ADMINISTRATION. ☘
Cefazolin at a dose of 2 g intravenously or intramuscularly is most commonly used.

☘ POSITIONING AND ANESTHESIA. VISUALIZATION. ☘
Patient positioning depends on the access route to the vertebral bodies.
After prepping the surgical field, the affected level is determined by fluoroscopy using an angiograph. Local anesthesia is administered to the skin, underlying soft tissues, and periosteum.

☘ ANESTHESIA. ☘
Anesthesia includes neuroleptanalgesia and local anesthesia with 1-2% lidocaine injected in layers according to the planned needle path. For patients with severe pain or lesions in the cervical spine, general anesthesia is preferable.
The vertebroplasty procedure—puncture of the vertebral body with a special trocar needle, subsequent venography (phlebospondylography), and cement injection—is performed under angiographic guidance.

☘ ACCESS ROUTES TO VERTEBRAL BODIES. ☘
The needle insertion technique depends on the level and extent of the lesion. For thoracic and lumbar vertebrae, transpedicular, parapedicular (transcostovertebral), and posterolateral approaches are used. For cervical vertebrae, anterolateral and transoral approaches are preferred.

☘ TRANSPEDICULAR ACCESS. ☘
This approach offers clear anatomical landmarks, allows adequate biopsy and vertebroplasty, and carries relatively low risk of damaging vital structures during needle insertion.

For cervical procedures at levels C2 to C7, the anterolateral approach is used. In this case, the operator manually displaces the carotid artery laterally and the midline neck organs (trachea and esophagus) medially from the needle entry site.

☘ PHLEBOSPONDYLOGRAPHY. ☘
This is the second crucial step in percutaneous vertebroplasty. Phlebospondylography helps assess venous drainage at the target level but cannot reliably predict cement leakage during the procedure due to differences in viscosity between the contrast agent and bone cement.

After preparing the mixture (mixing liquid monomer with powder polymer), once the cement reaches optimal viscosity, the vertebral body is filled with cement. Cement is injected either via a high-pressure syringe or a device combining a mixer and syringe.

The injection of bone cement is the final step. There is no clear correlation between cement volume and pain reduction. Barrett et al. report that injecting 2–3 ml for thoracic and 3–5 ml for lumbar vertebrae results in pain relief in 97% of cases.

After injecting the necessary amount of cement under fluoroscopy control, filling the vertebral body defects and achieving sufficient cement strength, the needle is removed, soft tissues compressed locally for hemostasis for 5 minutes, and an aseptic dressing is applied.

POSTOPERATIVE CARE AFTER PERCUTANEOUS VERTEBROPLASTY

Patients must remain on bed rest for one hour after the procedure. Vital signs and neurological status should be checked every 15 minutes during this period.

During this time, PMMA cement reaches 90% of its maximum hardness. If no complications occur, the patient may sit up in bed with assistance after one hour.

A follow-up CT scan (preferably spiral CT) of the treated level should be performed to visualize cement distribution. Pain reduction of up to 50% usually occurs within hours after the procedure, but pain may occasionally increase. In such cases, analgesics and NSAIDs are recommended for 1–2 days.

Afterward, the patient remains lying down for 1–2 hours while vital signs and neurological status are monitored for any worsening of symptoms.